You may feel commenting on bot use isn't relevant.
I disagree.
The idea behind curation is for good content to be upvoted more than not so good content, and bots break that. He's not even flagging those posts, as is @heimindanger's bot. He's just pointing it out, which is a valuable contribution to the conversation.
So, it's not spam. It is relevant to the author's work, because the author's aren't potentiating curation, they are breaking it.
I would agree if all the “money” was reviewing and rewarding. They are selling their votes. Then you have others delegating sp for return. So the problem is deeper than the people using the bots.
None of that is possible without the buyers of votes.
And your reply isn't responsive to my point, which is that comments about votebuying aren't spam on posts that buy votes.